1. Field of the Invention
The present invention generally relates to a vehicle driving force control apparatus. More specifically, the present invention relates to a vehicle driving force control apparatus that calculates a target driving force for a vehicle that corresponds to a driver""s request and achieves the calculated target driving force by controlling an actual driving force generated by a drive train of the vehicle.
2. Background Information
One example of a vehicle driving force control apparatus of prior art is described in Japanese Laid-Open Patent Publication No. 2001-105932. The vehicle driving force control apparatus described in this publication is configured to obtain a requested vehicle driving force when traveling on connecting roads that join highways with general roads. This vehicle driving force control apparatus revises a normal target driving force that is calculated based on the accelerator operation amount and vehicle speed toward a larger value when it is determined that the vehicle is traveling on a connecting road that joins a highway with a general road.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved vehicle driving force control apparatus. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.
It has been discovered that, with the vehicle driving force control apparatus of prior art described above, there are situations in which the target driving force is revised to a larger value even when increasing the driving force is not desirable. For example, when this vehicle driving force control apparatus detects that the vehicle is on a connecting road that joins a highway with a general road based on map data from an onboard navigation system, it revises the target driving force to a larger value even though the vehicle was traveling at a low speed and increasing the driving force was undesirable. Since the target driving force is revised to a larger value, the driver has to back off the accelerator to maintain the vehicle speed.
The present invention was conceived in view of this problem. One object of the present invention is to provide a vehicle driving force control apparatus that can both eliminate unnecessary accelerator operation by the driver and respond suitably to zone attribute changes by taking into consideration a requested driving force requested by the driver when controlling the target driving force compensation in response to zone attributes.
In order to achieve the aforementioned object, a vehicle driving force control apparatus is provided that comprises a zone attribute detecting component, a requested driving force detecting component and a target driving force computing component. The zone attribute detecting component is configured and arranged to detect at least two different zones with different zone attributes in which a vehicle travels. The requested driving force detecting component is configured and arranged to detect a requested driving force requested by a driver. The target driving force computing component is configured to calculate a target driving force based on a requested driving force that is adjusted by a final compensation driving force. The target driving force computing component includes a zone attribute compensation control section and a compensation driving force upper limit value setting section. The zone attribute compensation control section is configured to calculate a compensation driving force according to which of the zone attributes is being detected. The compensation driving force upper limit value setting section is configured to set an upper limit value for the compensation driving force according to an amount of the requested driving force that is detected by the requested driving force detecting component. The target driving force computing component is further configured to set the final compensation driving force as a value that is obtained by limiting the compensation driving force calculated by the zone attribute compensation control section with the upper limit value of the compensation driving force.
These and other objects, features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention.